title: New types of toxin A-negative, toxin B-positive strains among clinical isolates of Clostridium difficile in Australia.
abstract: A total of 817 human clinical isolates of Clostridium difficile from all Australian states were screened for A(-)B(+) strains by toxin gene PCR assays. Nine (1.1 %) strains were confirmed to be A(-)B(+) by enzyme immunoassay for toxin production. Of these, six (66.7 %) were binary toxin-positive by PCR. Using PCR ribotyping and toxinotyping, the A(-)B(+) strains could be grouped into seven ribotypes and three toxinotypes. Only one of the ribotypes had been reported previously (017). The prevalence of ribotype 017 was low in this study with only two strains detected. Two new A(-)B(+) toxinotypes were also defined (XXX, XXXI). Toxinotype XXX had a toxin B gene similar to that of toxinotype IV (A(+)B(+)) but with a novel cytopathic region. Toxinotype XXXI was similar to other A(-)B(+) types (X, XVII), but had a larger deletion to the toxin A gene than in either of those types. The types of A(-)B(+) strains identified in this study differed markedly from those described in other regions.
authors.affiliation: Microbiology & Immunology, The University of Western Australia, Nedlands 6009, Western Australia, Australia.
authors.forename: Briony
authors.initials: B
authors.lastname: Elliott
authors.affiliation: Microbiology & Immunology, The University of Western Australia, Nedlands 6009, Western Australia, Australia.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Squire
authors.affiliation: Division of Microbiology & Infectious Diseases, PathWest Laboratory Medicine, Nedlands 6009, Western Australia, Australia.
authors.forename: Sara
authors.initials: S
authors.lastname: Thean
authors.affiliation: Microbiology & Immunology, The University of Western Australia, Nedlands 6009, Western Australia, Australia.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Chang
authors.affiliation: Anaerobe Reference Unit, Cardiff, Wales, UK.
authors.forename: Jon S
authors.initials: JS
authors.lastname: Brazier
authors.affiliation: Institute for Public Health, Maribor, Slovenia.
authors.forename: Maja
authors.initials: M
authors.lastname: Rupnik
authors.affiliation: Division of Microbiology & Infectious Diseases, PathWest Laboratory Medicine, Nedlands 6009, Western Australia, Australia.|Microbiology & Immunology, The University of Western Australia, Nedlands 6009, Western Australia, Australia.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Riley
mesh_terms: D001315:Australia / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D016360:Clostridioides difficile / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D003015:Clostridium Infections / Q000453:epidemiology / Q000382:microbiology*; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D016133:Polymerase Chain Reaction; D021521:Ribotyping
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile